Posted by Adam Voorhes (68.6.73.86) on September 22, 2003 at 22:41:44:
In Reply to: Fugi Velvia 50 posted by bob on September 22, 2003 at 16:06:12:
Kodak and Ilford have pretty decent reciprocity charts in their tech data sheets& I looked at Fujis for Velvia (http://www.fujifilm.com/JSP/fuji/epartners/bin/AF3-960E.pdf) and all it had was info up to 32 seconds (+1 stop). Not much help. Hmmm, I found some more data saying that a 60 sec. exposure would be 160 seconds& still not much help. Assuming that that pattern continues (reciprocity can be a fairly straight line& but it may not be) this would be a decent starting place...
30 x 2 seconds = 60 seconds
60 x 3 sec = 180 sec (actually 160, but on the data I found, but assuming the line will curve up in the first few minutes this may be a better solution)
120 x 4 sec = 480 sec
240 x 5 sec = 1200 sec
(8 minutes) 480 x 6 sec = 2880 sec (48 minutes)
and so on from there... may be a good place to start. Let me know what you find!